Screen stencilling machine, reciprocating type



J. A. BLACK July 31, 1962 SCREEN STENCILLING MACHINE, RECIPROCATING TYPE Filed Nov. 24, 1961 3 Sheets-Sheet 1 INI/Ewan. Tanzes A. Black @www 5 Sheets-Sheet 2 J. A. BLACK SCREEN STENCILLING MACHINE, RECIPROCATING TYPE FFT.. Ov

July 31, 1962 Filed Nov. 24,

ATTORNEY J. A. BLACK July 31, 1962 SCREEN STENCILLING MACHINE, RECIPROCATING TYPE Filed NOV. 24, 1961 3 Sheets-Sheet 3 ATTORNEY nite 3,545,836 Patented July 3l, 1562 ice 3,046,880 SCREEN STENQILLENG MACLINE, RECEPRCATENG TYPE James A. Black, General Research and Supply Co., 572 Division Ave. S., Grand Rapids, Mich. Filed Nov. 24, 1961, Ser. No. 157,031 16 Claims. (Cl. 1111-123) The present invention relates to screen stencilling machines.

The primary objects of the invention are to provide a screen stencilling machine which is especially adapted for screening coating material onto articles to produce small inscriptions or designs such as trademarks, titles, company names, part numbers and the like, and particularly onto articles of irregular shape which cannot be fed through conventional automatic stencil screen presses for printing on at or sheet stock; to provide such a stencilling machine which is semi-automatic in operation; to provide such a machine which can readily be installed on conventional work tables or benches; to provide such a stenciling machine in which the stencil may quickly be removed and replaced with a ditierent stencil; to provide such a stenciling machine which is pneumatically operated; and in general to provide such a screen stencilling machine which is simple and economical in construction and eliicient in operation.

An illustrative embodiment of the invention is shown in the accompanying drawings, wherein:

FIGURE l is a perspective view of a work table having the new stencilling machine built therein;

FIGURE 2 is a fragmentary top plan view of a portion of the work table and the stencilling machine;

FIGURE 3 is a vertical sectional view thereof, the plane of section being indicated by the line 3-3 ot' FIG- URE 5, and with operating parts of the machine shown in the positions which they occupy at the beginning of a print stroke of the machine;

FIGURE 4 is a vertical sectional view thereof, similar to FIGURE 3, and showing the operating parts of the machine in the positions which they occupy upon the completion of a print stroke;

FIGURE 5 is a horizontal sectional View of the machine taken on line 5-5 of FlGURE 3; and

FIGURE 6 is a horizontal sectional View thereof taken on line 6-5 of FIGURE 3.

Referring now in detail to these drawings, the work table 11i shown in FIGURE 1 has a rectangular opening 1'1 in the middle of the table top 12, in which opening is mounted a rectangular stencil frame 13 desirably made of wood and having a stencil screen 14 of silk or iine wire mesh secured to the upper surface thereof as by means of staples or a suitable adhesive. A metal box 15 is fastened to the underside of the table top 12 beneath the stencil screen by means of angle brackets 16 secured as by screws 17 to the box 15 and by screws 18 to the table top v12. Other screws 19 removably secure the stencil frame 13'in position in the table tops opening 111, said screws -19 extending through the stencil frame and being threaded into the brackets `16.

A pair of parallel rods 20 extend longitudinally through the upper part of the box 15, being secured to the end walls of the box as by means of screws 21. A carriage 22 is mounted for reciprocal sliding movement on the rods 20. A block 23 is pivotally mounted on a horizontal pintle 24 extending transversely of the carriage 22. A rubber squeegee 25 is secured to the block 23 by means of screws 26 passing through a plate 27, through elongated apertures 28 in the squeegee 25, and threaded into the block 23. The elongation of the apertures 28 permits adjustment of the squeegee 25 on the block 23 relative to the stencil screen 14. The block 23 and squeegee 25 are swingable on the pintle 24 between a lowered position out of contact with the stencil screen 14 as seen in full lines in FIGURE 3, and a raised position contactingthe screen 14 as seen in full lines in FIGURE 4. In the lowered position of the squeegee, the plate 27 rests against an adjustment screw 29 threaded into the carriage 22.

A pneumatic cylinder 3G is pivotally mounted on the box 15 at the left hand end thereof as seen in the drawings, and exteriorly of the box. The cylinder has blocks 31 secured thereto as by welding, and these blocks 31 are journalled on pins 32 mounted on extensions 33 on the box 15. The cylinder has a piston 34 and piston rod 35 the outer or right hand end of which is bifurcated and pivotally connected by a pin 36 to a lug 37 on the block 23. Compressed air is admitted to the right hand end of the cylinder 30 to drive the piston rod 35 and carriage 22 to the left, through a conduit 38 having a valve 39 secured to the underside of the table top 12 and provided with an operating button 40 extending through the table top so as to be accessible to the operator. An exhaust port 41 is provided in the cylinder for the escape of air when the piston rod has completed its movement to the left to eiiect the print stroke of the machine. A spring 42 interposed between a collar 43 on the piston Irod 35 and the end wall of the box, effects the return or non-print stroke of the machine.

A dash pot 44 is secured to the end wall of the box 15, below the cylinder Sil, by means of screws 45. This dash pot 44 has a piston 46 and a piston rod 47 extending into the box and connected by a screw 45 to a bar 49 secured `to the carriage 22' by means of a screw 50. This dash pot elects the swinging movement of the squeegee 25 between its printing position and non-printing position as hereinafter more fully described. Valves 51 and 52 at the left end and right end respectively of the dash pot, are provided for regulating the action of the dash pot on the movements of the squeegee.

The lower part of the box 15 constitutes a reservoir for coating material 53, and means are provided for distributing some of the coating material onto the underside of the stencil screen 14 upon the completion of each print stroke of the machine, the squeegee being lowered out of contact with the screen during its returning, non-print stroke. The paint distributing means comprises a somewhat flexible metal distributing arm 54 secured to a shaft 55 journalled on the carriage 22 by means of a screw 56 passing through a plate 57, through the distributing arm 54, and threaded into a block 5S carried by the shaft 55. A lever arm 59 mounted on one end of the shaft 55 (the near end as seen in the drawings) is adapted to contact a stop screw 60 mounted in the adjacent wall of the box 15 during the nal phase of the carriages print stroke to the left, thus to rotate shaft 55 counter-clockwise and swing the distributing arm 54 upwardly to splash a quantity of coating material onto the underside of the stencil screen. During the return or non-print stroke the weighted portion 61 of the lever arm 59 returns the distributing arm 54 into the coating material.

A guard or shield in the form of a length of angle bar 62 secured by screws 63 to the block 23, conducts any coating material that may drip from the stencil screen 14 to the opposite sides of the boxs interior thus shielding the operating parts of the machine so that they do not become clogged with the coating material.

Operation Unstencilled articles such as the rubber pads 70- shown stacked on the table at the right in FIGURE 1, are placed one by one on the flat, stock-supporting upper surface of the table over Ithe stencil 14. After each artcle is placed in position, the operator depresses the button 40 of the air valve 39.* Compressed is thus admitted to the right hand end of cylinder 30, moving piston 35 to the left to eiect the print stroke of the machine. The initial phase of this movement is'resisted by piston 46 moving-in dash pot 44 soth-at the squeegee 25 is 'swung upwardly into contact with the stencil screen 14 as seen in dotted lines in FiGURE 3 and in solid lines'in FIGURE 4, thus to force coating material through the stencil and Y to lower position out of Contact with ythe stencil screen,

and returns the carriage 22' toV its initial starting position. Stencilled articles 71 are shown at the lleft ofthe table in FIGURE 1. y

The stencilling machine can be installed in Aany suitable V.element having a iiat, stock-supporting surface and the required opening therethrough for the stencil 'ame.

Among the ladvantages of `this stencilling unit are its adaptability for use in plants where compressed air is available, its extreme simplicity, its -adaptability for stencilling small inscriptions on articles of various sizes and shapes, the ready removability of the stencil frame 13 for replacement thereof or for replenishment of the coating material in the reservoir or box 15, and the fact that the coating material is completely enclosed in the box 15 so that its solvents do not readily evaporate. Y

' While but one specific lembodiment of the invention has been herein shown and described,vit will be understood that numerous details may be altered or omitted With- Vout departing from the spirit of the invention #as the same is deiined by the following claims. Y v I claim: Y

1. In a screen stencilling machine, in combination with a table tcp or the like having anat, stock-supporting upper surface and an opening therethrough: a stencil frame having a stencil screen thereon and mounted in said opening with the stencil screen substantially flush with the hat upper surface of the top; said machine including a reservoir containing "coating material and applying means for applying said coating material to said screen and a squeegee mounted on the underside of the top for reciprocating movements beneath thestencii to eiect print strokes during which the squeegee forces said coating material upwardly through the stencil screen and onto stock placed on the stock-supporting upper surface of said top, and returning non-print strokes during which the squeegee is out of contact with the stencil.

2. A screen stencillingrmachine according toY claim 1 in which said coating material is intermittently applied to the underside of the stencil screen in coordination with the reciprocating movements of the squeegee. 7

Q3. A'screen stencilling machine according to claim 1 characterized 'by having said reservoir of coating material secured to the underside of the -top beneath the stencil, and means operable at the end of each print stroke kto splash `a quantity of coating material upwardly from the reservoir and onto the underside of the stencil screen.

' 4. A screen stencilling machine according to claim 1 characterized by having @a pneumatic cylinder and piston operatively connected to the squeegee for eiecting the print strokes, and spring means -for eiecting the non-print strokes.

5. Ina screen stencilling machine, in combination with a table top or the like having a flat, stock-supporting upper surface .and an opening therethrough: a stencil frame having a stencil screen -thereon and mounted in said opening' with the stencil screen substantially ush with the flat upper surface of the top; a box depending from the underside of said top beneath the stencil, the

lower part of the vbox constituting a reservoir for coating material; a squeegee mounted in the upper part of the box for reciprocating movements beneath the stencil to eect print strokes during which the squeegee forcesV coating material upwardly through the stencil. screen and V onto stock placed on the stock-supporting upper surface of said top, "and returning non-print strokes during which the squeegee is out of contact with the stencil; and screencoating means associated with the stencil and'operable at the end of each print stroke to splash a quantity of coating material upwardly from the reservoir and onto` the underside of the stencil. Y t

6. A screen stencilling machine according to claim `5 characterized by having a pair of parallelV rods mounted longitudinally in Ithe upper part of the box, a carriageA reciprocally mounted on said rods, and means for mounting the squeegee on said carriage for swinging movement between a printing position pressingragainst the underside of the stencil during the print strokes and a position out of contact with the stencil during the non-print strokes.

7. A screen stencilling machine according to claim 6 characterized by having a' pneumatic cylinder mounted on one end wall of the 'box and having a piston movableY in the cylinder and a piston rod operatively connected to the carriage for moving the carriage in the direction of lthe print stroke.

8. A screen stencillingrmachine Iaccording to claim 7 V the .start of the non-print stroke.

lil() 10. A screen stencilling machine comprising a top having a fiat, stock-supporting upper surface providedV with an opening, -a stencil assembly mounted 0n the underside of said top in registry with said opening therein Vand iucluding a frame having a stencil screen'thereon mounted in the opening with the stencil screen substantially iluSh with the flat upper surface of the top, said stencil assembly -aiso including a reservoir having an open top in register with said opening, applying means connected to said stencil assembly for iapplying'coating material contained within the reservoir Ito Ithe underside ofY said stencil screen at selected intervals, and means mounted Yfor movement within said reservoir including la squeegee beneath said.

stencil and movable .into engagement therewith to force said coating material upwardly through the stencil screen and onto stock placed on the stock-supporting surface oriY said top.

l1. A screen stencilling machine comprising a top hav-V ing a flat, stock-supporting upper surface provided with an opening, a stencil assembly mounted on the underside of said top'in registry with said opening therein and including a frame having a stencil screen thereon for movement within said reservoir including a squeegee beneath said stencil and movable into engagement therewith to force said coating material upwardly through the stencil screen and onto stock placed on the stock-supporting surface on said top, said means also including guide rails fixed within said reservoir, a carriage reciprocably, mounted on said guide rails, and a block pivotally mounted at one end on said carriage and extending upwardly therefrom toward said screen, said squeegee being carried by the upper end of said block remote from said carnage.

l2. A screen stencilling machine comprising a top having a at, stock-supporting upper surface provided with an opening, a stencil assembly mounted on the underside of said top in registry with said opening therein and including a frame having a stencil screen thereon mounted in the opening with the stencil screen substantially flush with the flat upper surface of the top, said stencil assembly also including a reservoir having an open top in register with said opening, means mounted for movement within said reservoir including a squeegee beneath said stencil and movable into engagement therewith to force coating material contained within the reservoir upwardly through the stencil screen and onto stock placed on the stock-supporting surface on said top, said means also including guide rails iixed Within said reservoir, a carriage reciprocably mounted on said guide rails, a block pivotally mounted at one end on said carriage and extending upwardly therefrom toward said screen, said squeegee being carried by the upper end of said block remote from said carriage, means mounted on said reservoir and connected to said block intermediate the ends thereof for moving the carriage in one direction relative to said guide rails, and means connected to said carriage for resisting movement of the carriage in said one direction of its travel whereby to cause said block to be pivoted upwardly such that the squeegee contacts said stencil screen as the carriage is moved in said one direction.

13. The assembly as dened in and by claim 12 wherein the last mentioned means is in the form of a dash pot.

14. A stencilling machine comprising a top having a at upper work supporting surface, said top being provided with an opening therethrough, and a stencilling assembly supported by said top on the underside thereof, said stencilling assembly including a frame xed within said opening and carrying a stencilling screen substantially ush with the work supporting surface of said top, a reservoir iixed to the undersurface of said top and having an open top in register with said opening, a pair of horizontal, transversely spaced guide rails mounted in said reservoir, a carriage reciprocably mounted between said guide rails and including a block pivotally attached at one end thereto to the carriage and extending upwardly therefrom toward said stencil, a squeegee mounted on said block at the upper end thereof and extending upwardly therefrom toward said stencil to terminate in closely spaced relationship therebeneath, a piston rod pivotally attached at one end to said block at a point thereon above the pivotal attachment thereof to said carriage, a cylinder mounted on said reservoir receiving said piston rod and there being a piston at the free end of said piston rod reciprocable within said cylinder, a spring surrounding said piston rod and normally urging the same in one direction to move said carriage to one end position relative to said guide rails, pneumatic means connected to said cylinder for forcing said piston and piston rod in opposition to said spring, and motion retarding means mounted on said reservoir and iixed to said carriage for opposing movement thereof in at least that direction of movement of the carriage as elected by said pneumatic means.

15. A stencilling machine comprising Ia top having, a at upper work supporting surface, said top being provided with an opening therethrough, land a stencilling 'assembly supported by said top on the underside thereof, said stencilling assembly including a frame fixed within said opening and carrying la stencilling screen substantially ush with the work supporting surface of said top, a [reservoir xed to the undersurface of said top and having an open top in register with said opening, a pair of horizontal, transversely spaced guide rails mounted in said reservoir, a carriage reciprocably mounted between said guide rails and including a block pivotally attached at one end thereto to the carriage and extending upwardly therefrom toward said stencil, a squeegee mounted on said block at the upper end thereof and extending upwardly therefrom toward said stencil to terminate in closely spaced relationship therebeneath, a piston rod pivotally attached at one end to said block at e point thereon above the pivotal attachment thereof to said carriage, =a cylinder mounted on said reservoir receiving said piston rod and there being a piston at the free end of said piston rod reci-procable within said cylinder, a spring surrounding said -piston rod Iand normally urging the same in one direction to move said carriage to one end position relative to said guide rails, pneumatic means connected to said cylinder for forcing said piston and piston rod in opposition to said spring, motion retardiug'means mounted on said reservoir and txed to said carriage `for opposing movement thereof in `at least that `direction of movement of the carriage as eiected by said pneumatic means, said motion retarding means comprising a dash pot.

:16. A stencilling machine comprising 'a ltop having a at upper work supporting surface, `said top being provided with an opening therethrough, y.and -a stencilling assembly supported by said top on the underside thereof, said stencilling assembly including Ia frame fixed Within said opening and carrying =a stencilling screen substantially flush with the work supporting surface of said top, la reservoir fixed to the undersurface of said top and having lan open top in register with said opening, a pair of horizontal, transversely spaced guide nails mounted inl said reservoir, a `carriage reciprocably mounted between said guide rails and including a block pivotally attached at one end thereto to `the carriage land extending upwardly therefrom toward said stencil, la squeegee mounted on said block at the upper end thereof and extending upwardly therefrom toward said stencil to terminate in closely spaced relationship Uherebeneath, a piston rod pivotally attached at one end to said block at a point thereon above the pivotal attachment thereof to said carriage, a cylinder mounted on said reservoir receiving said piston rod `and there being 'a piston iat the free end of said piston rod reciprocable within said cylinder, a spring surrounding said piston rod and normally urging the same in one `direction to move said carriage to one end position relative to said guide rails, pneumatic means connected to said cylinder for forcing said piston and piston rod in opposition to said spring, motion retarding means mounted on said reservoir and ixed to said carriage for opposing movement thereof in at least that direction of movement of the carriage as effected by said pneumatic means, `and means pivotally mounted on said carriage land depending therefrom into -a quantity of coating material contained within the reservoir and being effective to splash ta quantity of coating material upwardly from the reservoir supply onto the underside of the stencil screen in one position ot" said carriage.

No references cited. 

